One notable Google Drive PDF feature is Optical Character Recognition (OCR). When you have a PDF where the text was saved as an image, you typically can’t search it. However, if you save it in Google Docs, it becomes searchable.

In my test, it got rid of the image that was in the document, and stripped the text of their color and fonts.

You could use it to scan photographs of receipts, handwritten notes, and other paper items into PDF format with the Google Drive mobile Android App. Google Drive will also get rid of the background, and make sure that the PDF it saves is high-contrast and easy to read.

Google Drive also lets you connect to a host of other online apps from the Chrome App Store to give you other PDF editing abilities.

2. Nitro’s PDF Converters

If all you need is your Word doc to or from PDF, or a PDF to Excel or Powerpoint, you have got to check out Nitro’s suite of online converters.

All you have to do is click on the drop down to choose what file type you’re converting to or from, select and upload the file for converting, and enter your email address. Nitro will convert the file and email it straight to your inbox. It couldn’t be easier.

You can also add a few types of form fields like checkboxes, radio buttons, and text boxes for people to fill in. You’ll have to make sure to draw rectangles around the form fields though to make it clear that they’re interactive spaces upon download.

PDFescape also lets you easily modify the document as a whole, letting you move, rotate, crop, and add extra pages from other PDF documents.

Additionally, PDFescape no longer adds a watermark logo to the forms you save – hooray!

Occasionally, you might need to combine different files into a PDF. Rather than convert spreadsheets, docs, and slides each into PDF and then combine those into a single PDF, Online2PDF lets you convert and merge up to 20 different files together in one fell swoop.

PDFfiller’s main offering is to make it easy for you to fill in PDFs. You can add text, checkmarks, Xs, circles, dates, pictures, and even add e-signatures easily.

One of the coolest aspects of PDFfiller are the many ways it lets you sign a document. You can draw it on a touchscreen, use your mouse, type it as text, photograph a signature with your webcam, or upload an image.

I tested the webcam function, and it works great. You sign a sheet of paper and hold it up to the camera, align it in a blue rectangle space, and it captures it. Then it automatically strips away the background.

You can then change the brightness and contrast, and edit your signature as needed to make sure your signature appears the way you like it.

No longer will you have to deal with the hassle of printing out pdf forms, signing, and scanning the whole thing back just to get a signature on it. Brilliant.

PDFfiller also has an extensive array of ways you can import documents to it. You can upload documents, import PDFs from a URL, connect it to 3rd party cloud services like Google Drive, Dropbox, Box, or OneDrive.

Like many services, Office Online will let you download files to PDF format.

Office Online will also let you open converted copies of PDF files in Word for editing, too. What’s unique here is you can edit the content of the original file, unlike other services that just let you add to it or fill in forms.

I tested it with a PDF of mine. Word Online warns that the layouts sometimes change, and like it said, it doesn’t necessarily hit the mark adequately.

Office Online has no trouble with layout when things flow from top to bottom, but it doesn’t necessarily parse parts that sit side-by-side. It gets colors and images right. However, it doesn’t have all the fonts that could possibly be in the PDF, so that might change.

Office Online seems to try to choose fonts that look similar to the original, which works for documents where the font wasn’t very important. It doesn’t really work at all if you’ve chosen your font carefully though for a graphic or layout design. You’ll really just have to try it yourself to see if it handles your PDF well enough.

What’s Your PDF Challenge?

PDFs are kind of a tricky file type: they’re designed to render properly everywhere, and they’re not supposed to be easy to edit. However, we all need to edit them from time to time.

What annoys you about working with PDFs? Which workarounds have you found? Comment below to let us know about your favorite, under-appreciated software that helps you out with them – we’d love to hear about it.

The question was "How to Edit All Your PDF Files Online". Ie. add text, annotations, highlight text etc. Only PDFescape and PDFfiller can do this job. If "Online" is not a requirement then PDFXchange editor (free) and the latest versions of Acrobat Reader do the job. For Linux users, okular has some capabilities but it is still under development (I recommend using the online applications).